Ultimate Strength of Metals Accurately Predicted With New Theoretical Model

A new model is able to accurately determine the peak strength of polycrystalline metals.

To build safe and robust automobiles, spacecraft, and other technology, scientists attempt to know as much as possible about various metals’ properties. However, these properties can be tricky to estimate without extensive testing. Now, researchers have created a theoretical model able to estimate various pure and alloyed metals’ ultimate strength — a measurement defined as the amount of force necessary before a metal will deform.

The image shows the transformation of a crystalline metal (upper left) to amorphous material (lower right), with an energy difference related to the heat of fusion. The graph in the upper right shows a representative plot of strength vs. crystallite (grain) size and includes the predictions from the model (red line) compared to experimental (x) and simulation (o) data. The graph in the lower left shows the model predictions for grain boundary energies of a variety of metals compared to density functional theory calculations from the literature. Credit: Chandross and Agribay. Physical Review Letters (2020)

The framework, created by Chandross and Argibay of Sandia National Laboratories, does not require fit parameters. It relies on the connection between ultimate strength and thermodynamics and was able to accurately predict the ultimate strengths of nearly 20 different metals.” The new model could improve research and development in many industries by allowing scientists to better understand the potential maximum achievable strengths of alloys and explore new design alternatives.

Reference: “The Ultimate Strength of Metals” by Michael Chandross and Nicolas Argibay, 25 March 2020, Physical Review Letters.
DOI: 10.1103/PhysRevLett.124.125501

American Physical SocietyMaterials ScienceMetal